1. Field of the Invention
The present invention relates to a blood collection holder with an engaged blood collection needle and a companion biohazard receptacle for disposal of a needle and, more particularly to a blood collection system comprised of means in which a blood collection needle engaged to a holder is irreversibly positively locked when inserted into a needle removal device of a biohazard receptacle, thereby preventing withdrawal of the needle from the biohazard receptacle, following which the needle is unthreaded from the holder and disposed inside the receptacle.
2. Description of the Prior Art
To obtain a blood sample, blood is drawn into an evacuated blood collection tube through a double ended needle. The needle includes a hub, an anterior needle for tissue penetration into a blood vessel and a posterior needle having an exterior elastomeric valve. The posterior end of the needle is penetrably inserted within a holder having female threads for threadedly engaging the hub to retain the double ended needle positionally fixed with respect to the holder. A common example of this conventional holder is sold under the brand name VACUTAINER.RTM.. The proximal end of the holder is open to receive an evacuated blood collection tube having a stopper for penetrably receiving the posterior needle. During venipuncture, blood will flow through the anterior needle and the posterior needle into the collection tube. When the collection tube is removed, the elastomeric valve recovers the posterior needle to prevent spontaneous blood flow from the needle. Upon completion of the venipuncture procedure, the anterior needle is withdrawn from the patient's vein. While the holder is often reused, the double ended needle must be safely removed from the holder, without causing needle stick and contact with the contaminated needle. Typically, a conventional biohazard receptacle for needles is provided with a lid having various shaped slots to engage the needle hub. To dispose of a used needle, the phlebotomist must carefully place the exposed needle hub into the slot, grip and rotate the holder to unthread the needle and cause the disengaged needle to drop completely through the slot into the underlying container. A danger arises after the needle is disengaged from a holder if the hub remains engaged in the slot, causing upstanding exposure of the posterior needle. The user must manually disengage the hub from the slot to permit the needle to drop into the receptacle. In addition, when the hub is engaged in the slot, there is no positive locking mechanism to irreversibly grip the needle hut and prevent the needle from moving outwardly from the slot. Thus a user may engage the needle hub into a slot, incompletely unthread the needle from the holder, lift the holder with the partially attached needle away from the biohazard container which will cause dangerous exposure to a used needle. Aside from hub engaging slots, other devices have been developed including the use of fixed and movable jaws to engage the needle hub. These devices exhibit a positive locking means for retaining the needle in the needle removal mechanism. These positive locking means are reversible to allow release of a disengaged needle from the needle removal mechanism. Thus, the user can be endangered if the positive locking means is prematurely released, allowing exteriorization of the needle from the biohazard receptacle. Mechanized devices for unthreading a double ended needle are also known but these mechanisms also lack irreversible positive locking means which can potentially cause the needle to exteriorize outside of the biohazard devices.
A recently available reusable safety blood collection holder (i.e. ACCI-GUARD.RTM. HOLDER which is described in co-pending patent application: BLOOD COLLECTION TUBE HOLDER, Ser. No. 430,311), includes an insert for engaging the double ended needle. The insert is translatable within the holder to fully enclose and shield both the anterior and posterior needles of the double ended needle. The holder includes an anterior collar for shielding the pointed end of the anterior needle upon posterior retraction of the insert within the holder. Known syringe and needle removal mechanisms are not well suited for receiving and disposing needles from such devices since the hub of the double ended needle is shielded by the anterior collar and is not accessible for gripping by the opposed edges of a slot, jaws or the like.
In co-pending applications, DISPOSAL FOR NEEDLES AND SYRINGES (Ser. No. 536,708) and DISPOSAL FOR DISENGAGING AND RECEIVING NEEDLES (Ser. No. 536,378), biohazard receptacles with needle removal mechanisms are described. These two co-pending patent applications describe needle removal devices which are compatible with currently available holders of the VACUTAINER.RTM. and ACCI-GUARD.RTM. types, creating a safety blood collection system. However this safety blood collection system has no structural means to ensure that a double ended blood collection needle is irreversibly positively locked when inserted into the needle removal devices, which would prevent withdrawal of the needle from the biohazard receptacle.